Method for producing multi-component cases

Abstract

The invention relates to a method for producing cases, in which a case sleeve is formed from thin sheets, forming at least one element over an insert, a form or a cavity reproducing the conicity, the shoulder and the mouth that are characteristic of the case. The invention also relates to a product produced by the method, such as an ammunition case.

The invention claimed is: 
     
       1. A method for manufacturing bullet ammunition cases, each case comprising at least one main taper-shaped portion, a shoulder, a mouthpiece and a cap, wherein at least one of the main taper-shaped portion liner, the shoulder, and the mouthpiece are formed from at least one thin strip by shaping said at least one thin strip in the shape of a tube and forming said at least one of the main taper-shaped portion, the shoulder and the mouthpiece of the case on a die, wherein a plurality of dies is slid within and arranged one after the other in said tube before said forming. 
     
     
       2. The manufacturing method according to  claim 1 , wherein the main taper-shaped portion, the shoulder and the mouthpiece are formed from the same strip. 
     
     
       3. The manufacturing method according to  claim 1 , wherein the main taper-shaped portion, the shoulder and the mouthpiece are formed from different strips. 
     
     
       4. The manufacturing method according to  claim 1 , wherein said at least one thin strip is a flat strip before being shaped into said tube. 
     
     
       5. The manufacturing method according to  claim 4 , wherein the tube is closed by a weld achieved by welding means comprising at least one of electron beam or laser. 
     
     
       6. The manufacturing method according to  claim 1 , wherein the tube is shaped on the die by any one of a mechanical, an electromagnetic, a pneumatic, and a hydraulic operation. 
     
     
       7. The manufacturing method according to  claim 1 , wherein the shape of the dies and the spacing with the following die are designed in such a way that the thickness of the wall at the mouth of the case is controlled. 
     
     
       8. The manufacturing method according to  claim 1 , wherein the dies are composed of different elements, these elements may be of different materials and some elements may include radial or longitudinal clearances adapted to the welding modes. 
     
     
       9. The manufacturing method according to  claim 1 , wherein the material of said at least one thin strip is selected from any one or more of stainless steel, normal steel, brass, aluminum, or an alloy of any of the foregoing.